Refrigerating apparatus



Filed July 1931 3 Sheets-Sheet 1 Oct. 20, 1936. E F, SCHWELLE 2,057,746

REFRIGERATING APPARATUS Filed July 5, 1931 3 Sheets-Sheet 2 z' 97 "nl 1W mwa Patented a. 2o, icas 2,057,146 aErmGEaArnvG APPARATUS )Edmund F.Schwellen', Dayton, Ohio, assignor, by

mesne assignments, to General Motors Corporation, a. corporation ofDelaware Application July s, 1931,' serial No. 543,583

16 claims. (ol. 22o-9) This invention relates to refrigerating apparatusand more particularly to the construction of cabinets, the walls ofwhich are heat insulated to prevent the passage of heat therethrough.

In the manufacture of insulated cabinets, it has been proposed to useair spacci in the walls thereof to prevent the transferof heattherethrough. Heretofore such practice has been unsatisfactory for thereason that radiant heat will pass freely through air, and, in addition,the convection currents set up therein will transfer large amounts ofheat therethrough. To overcome the transfer of radiant heat ithasbeenproposed to provide a'dead air space bounded by a thin bright metal foilor leaf such for instance `as bright aluminum foil, for insulatingpurposes.' By the term metal foil is meant thin leaves of metal eitherwith or without paper backing of such thickness that they can be'readily formed to any desired shape. It has been found that these brightmetallic surfaces of foil radiate but very little heat, and consequentlyit is possible to utilize air spaces lined withsuch bright surfaces inheat insulating cabinets. By reducing the size of the air space theother objectional feature of air space insulation, namely loss of heatby convection currents, is removed'in that convection currentsordinarily set up minimum. A

Attempts to adapt such thin bright metallic Vfoil to cabinetconstruction so as to utilize air spaces in the walls thereof forinsulating purposes have met with great difculty. In the rst place,thisfoil is extremely thin and consequently cabinets mu/st be soconstructed as to prevent rupturing'of the foil when such cabinets aresub- Jected to the slam test, a test involving the opening and closingof the cabinetdoor over prolonged periods of time. In addition, the foilmust be so supported within the cabinet wall as to maintain itsubstantially taut at alltimes, while at the same time vpreventing thetransfer of heat through Athese supporting means. Thirdly, the foilbeing metallic, has a tendency' to rattle or cause what is known as ametallic cry and great care must be taken to prevent or render inaudiblesuch cries or other noises.

Itis to such structure that my invention particularly relates, havingfor one of its objects t vprovide a cabinet construction 'having foilinsulation, that is, a cabinet capableof utilizing a thin brightmetallic foil to advantage, while at the same time eliminating most ofits disadvantages. v

More particularly it is an object of the invention to provide thecabinet construction wherein all metallic cries are adequately deadened,rupturing of the foil is prevented, and a proper spacing of the foil isprovided.l

are decreased to a A further object of the invention is to provide animproved foil construction whereby the layers of foil may be formed bywinding a continuous strip of foil continuously around four sides of thecabinet and to provide various constructions of insulated cabinetsadaptable for easy and economical assembling.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings, wherein a preferred form of the 4invention is clearly shown.

In 4the drawings Fig.' 1 is av vertical sectional view through the upperportion of a refrigerator cabinet embodying one form of the invention;

Fig. 2 is an enlarged view of an upper corner of Fig. 1;

Fig. 3 is a vertical sectional View along the line 3-3 of Fig. 1;

Fig. 4 is an enlarged view of an upper corner of the cabinet as shown inFig. 3;

Fig. 5 is a modied form of the corrugated strip shown -in Figs. 3 and 4;

Fig. 6 is another modified form of the corrugated construction shown inFigs. 3 and 4;

Fig."7 shows a form of foil having means to prevent metallic cry; v

Fig. 8 shows another form of foil having a modied means for preventingmetallic cry;

Fig. 9 shows the form of foil used in the insulation at the back of Fig.1;

Fig. 10 is a modified form of wond foil insula- Fig. 11 is an enlargedview of an upper corner of the insulation shown in Fig. 7;

Fig. 12 shows a modiiled form of spacing means shown in Figs. 10 and 11;

Fig. 13 is a section on the line I3-I3 of Fig. 11;

Fig. 14 is a section on the line ll-Il of Fig. 11;

Fig. 15 is a modified form of the corner construction shown in Fig. 2;

Figs. 16 and 17 are views illustrating the method of making the cornerpiece shown in Fig. 15, and

Fig. 18 shows a'modied form of cabinet construction.

In order to illustrate one aspect of my invention, Ivhave disclosed inFigs. 1 to 4 inclusive a refrigerator cabinet generally designated at20.

This cabinet includes a lower machinery compartment 2i 'formed by theupright corner mem'- bers 22 and the horizontal cross members 23.

, The food storage compartment 24 is supported above the machinerycompartment. This food compartment includes a liner 25 which, as shown,may be a one-piece metal porcelain lining secured at its front edges tothe horizontal cross beams 2.1 and similar upright beams, not shown.

from the exterior of the cabinet to the inner liner Sheets of metalcoated with porcelain or other suitable substances form the outer wallsof the cabinet. A sheet metal member 3|, preferably coated withporcelain, is provided for covering the rectangular door jamb. Chipboard32 is placed beneath the. sheet metal covering for preventing thechipping of the porcelain. An outer liner 33 of a somewhat similar shapeto that of the inner liner 25, but larger, is similarly secured at itsfront edges to the door jamb 21. A porcelain sheet metal covering 34 isprovided on the top of the cabinet spaced from the outer liner bychipboard 35 and the sides of the cabinet are similarly providedwithsheet metal covering 36 and 31, are also similarly provided with.chipboard 38 which is inserted between the coated sheet metal coveringand the outer lining. A sheet metal covering 39-is also provided o-n therear wall of the cabinet. A door 40 is provided in the front wall of thecabinet and has a frame 4| provided with an outer sheet metal covering42, preferably coated with porcelain, and an inner sheet metal covering43, also coated with porcelain.

Insulation is provided between the inner and outer walls of the cabinet,and more strictly speaking, between the inner'and outer liners 25 and33. Upon four sides of the walls of the cabinet the insulationpreferably takes the form of a plurality of alternate corrugated andnon-corrugated or plane sheets. As shown, sheets of foil 45 incorrugated form are spaced from each other by sheets of a suitable paper46 or similar fibrous material. 'I'his insulation is preferably providedby Winding a continuous strip of corrugated bright-metallicfoil togetherwith a continuous strip of paper about the inner liner of the cabinetbefore assembling the liner into the cabinet. 'Ihe corrugated foil andstrip of paper are preferably wound about four sides of the inner liner25a plurality of times as shown in Figs. 3 and 4. If desired, instead ofthe foil being corrugated and the paper being non-corrugated, the papermay be corrugated and the foil may be non-corrugated. In thisconstruction the non-corrugated sheet serves to prevent adjacentcorrugated -sheets from nesting together which would prevent theformation of the proper size of air spaces.

sides of the inner liner, the comers become By my improved constructionof alternate sheets offcorrugated foil and non-corrugated paper, aplurality of air spaces or cells are provided which are bounded bybright metallic foil and paper. 'I 'he bright metallic foil eectivelyprevents heat transfer by radiation and a plurality of small air cellshas always been considered an effective way to reduce heat leak byconduction and convection. Inasmuch as the bright metallic foil iscorrugated and held between sheets of paper, the rattling or metal cryof the foil is prevented.

In winding insulation of this type. about four rounded. When it isdesired to use this type of insulation in a.v cabinet ,having outerWalls with square corners, an insert 41 may be provided to fill in thespace between the rounded corners of the insulation and the squarecorners of the outer walls. These inserts 41 preferably comprise anouter container 48, preferably of paper or cardboard of suitable shape,and a suitably corrugated sheet of bright metallic foil 49 properlydistributed within the container 48. Such an insert effectively preventsany convection of air which may be present in the vacant pockets of theadj acentcorners of the winding. Such inserts may be omitted if desired.

In Fig. 5 there is shown a modied form of corrugated foil insulation inwhich the corrugations 50 are not immediately adjacent each other, butare spaced by intermediate straight portions 5I. This corrugated foil iswound along with a strip of ordinary paper 52 of suitable composition inthe same manner as described above. With this type of construction theamount offoil necessary is reduced and the air spaces are maintainedsince the sheets of foil are kept properly separated by the yspacedcorrugations. As in the rst described type of foil, the paper may takethe place of the corrugated foil and the foil may take the place of thepaper, that is, the papermay be vcorrugated similarly to the foil andhave spaced corrugations as shown at 50, while the foil may benon-corrugated.

In Fig. 6 there is shown another modied form of corrugated construction.In this modification the foil 53 is again shown as corrugated, and thepaper 54 is shown as non-corrugated. In this modification the tips ofcorrugations on one side are glued or cemented to one side of the paper.Such a construction strengthens the corrugations and facilitateshandling of the foil and paper. If desired, this foil and paper may beused in the form of individual sheets. As mentioned before, the papermay be corrugated and the foil maybe non-corrugate 1 In order toinsulate the rear wall of the cabinet, a frame 55 is provided which iswound in such a manner so as to provide air spaces bounded by the spacedsheets of bright metallic foil. The frame 55 preferably comprises arectangular wooden structure or other low conducting material. The foilisplaced upon the rectangular frame 55 in a peculiar manner. Acontinuous strip of foil is fastened to one edge of the rectangularframe 55. In Fig. 1, the foil is shown as having one end attached to thelower portion of the rectangular frame 55. 'Ihe foil is then firstrwound around the rectangular frame 55 for one complete turn 60, andthen spaced cardboard spacing members 56 and 51 are attached to oppositeends of the rectangular frame 55 over the rst turn or layer of foil 60and a complete turn 6I of foil is wound about these spacers 56 and 51.After this, a Wider pair of spacing members 58 are fastened to oppositeends of the rectangular frame vover the second turn of winding 6I aswell as the spacers 56 and 51, and a third turn 62 of foil is woundabout the pair of spacing members 58. After the third turn 62 ofwinding, a third pair of wider spacing members 59 are fastened to theopposite edges of the rectangular frame 55 over the third turn ofwinding 32 as well as the spacer members 58, and a fourth turn ofwinding 63 `is passed around the third pair of spacing "members 59. Inthis manner, a. slab of spaced foil insulation hasbeen produced by awinding method. Preferably the foil upon the frame 55 is embossed with asort of hammered effect as shown in Fig. 9 in order to prevent the metalcry of the foil 2,057,746 wound upon the frame 55. If desired, howeverparallel threads may be glued to one or both sides of the foil toprevent metal cry as shown in Fig. 7, or parallel ribbons of glue may beput upon the foil as shown in Fig. 8 to accomplish the same purpose. Thedoor 00 is provided with a similarly wound slab of insulation 00 betweenits inner land outer covering members or walls and the foil employedissimilarly treated to prevent metal cry.

In Figs. 10 to 15 another form of winding structure is shown. In Fig. 10there is shown an inner liner 1i about which a continuous strip of foilis wound to provide a plurality of layers of foil, 12 to 15 inclusive,in spaced relation. As better shown in Figs. 11, 13 and 14, the foil isprovided with threads 16 and 11, preferably arranged alternately oneither side of the continuous strip of bright metallic foil. This formof insulation is preferably constructed by fastening one end of thecontinuous strip of foil together with 'the threads upon opposite sidesof the foil to a portionl of an inner liner as shown at 18 in Fig. 10.Spacing members 19 to 82 inclusive having matched y-shaped grooves andcorrespending projections on opposite sides which are used to space thelayers ofthe strip of winding so as to provide air spaces therebetween.These spacing members are adapted to t along four of the edges of theinner liner and also upon each other. The winding is performed in thefollowing manner: after the continuous strip of -foil is attached to theinner liner as at 10, the

innermost spacing members 19 are fastened, preferably by glue or cement,to the four diagonally opposite edges about which the winding is to takeplace and the first turn of foil 12 passes around and rests upon thefour spacing members 19 which have been fastened to the inner liner;after the lrst turn is made, the spacing members 80 have their innergrooves glued or cemented in place on top of the rst turn of foildirectly outside 'of the spacing members 19; after the spacing members80 are put in place, a second turn of foil 13 is wound'about the spacingmembers 00 so as to provides. second layer of foil and thensimilaryspacing members 8| are placed at the four corners on top of thesecond layer of wound foil 13 directly outside of the spacing members 00and then a third turn of the wound foil is taken about the spacingmembers 8| and after this similar spacing members 82 are placed on thethird turn 1d of the wound foil directlyoutside of the spacing members0| and a fourth turn of foil is taken around the spacing members 02 andthe loose end of the foil is fastened to the outer layer of foil 19. Itwill be understood that the winding can be performed without the use ofthe threads 16 and,

11, if desired, but the threads are preferably employed to prevent therattling and the metallic cry of the foil and also prevent its ruptureduring the winding operation.V

In Fig. 12 a modified form of spacing members 03 is shown. These spacingmembers are similar to the spacing members 19 to 02 inclusive and alsoextend across the entire width of one of the edges of the inner liner1|. These spacing members t3 consist of cardboard formed into a hollowangle iron shape. These angular spacing members 33 are. preferablyprovided with gummed paper @il at their inner corner for attaching tothe preceding winding of foil so that the winding operation may befacilitated. By employing spacers of cardboard having hollow angularshape, the

conductivity through the spacing members is further reduced. In Fig. 12no supporting threads 16 and 11 are shown but these may be used in thismodication also, if desired.

1, In Fig. 15 there is shown a modied rear corner construction which maybe used with any suitable form of construction, for example, that shownin Figs. 1 to 4 inclusive, or in the construction shown in Figs. 10 to12 inclusive. By inspection of Figs. 1 and 2, it will be seen that inthe rear wall of the cabinet the air spaces provided by the foil woundabout the frame iiii extend to the top and bottom of the outer lining 33as well as to the sides of the outer lining 33 (not shown). The airspace next to the rear wall of the inner liner therefore extends to theouter liner 33. By this type of construction some of the heat out of thecabinet may leak into the food storage compartment in this manner,sometimes at a suiciently rapid rate to cause sweating upon the outercovering of the cabinet. In order to avoid this heat leakage, I haveprovided an insert 0|, shown in Fig. 15, which prevents the inner airspaces in the back wall of the cabinet from extending to the outer wall.In Fig. 15, the foil type of insulation |02 between the top wallsof thecabinet may be of any suitable type, for example, that shown in Figs. 1to 4 inclusive or that shown in Figs. 10 to 12 inclusive. The insulationbetween the back walls of the inner and outer liners |03 and |00 shownin Fig. 15 terminates opposite the top wall of the inner liner |03. Iheinsulation |02 between the top walls of the cabinet terminates oppositeVthe back wall of the inner liner |02. By thus shorteningv the back walland decreasing its width, a space is left around the perimeter aroundthe back wall of the cabinet. This space is preferably filled by theinsert |0|. This insert con.- sists of a plurality of quarter cylinders|06 to YH0 inclusive of thin cardboard having bright metallic foil lonone or both sides which are held in spa'ced relation by webs ofcardboard to H6 inclusive, which are glued or cemented thereto. 'Iheinserts are preferably formed in the following manner: the cylinders |06to ||0 inclusive, composed of cardboard having bright metallic foil onone or both sides, are placed in concentric relation and spacing discs II are glued into both ends of the smaller 'cylinder or tube |06, aconcentric spacingv ring ||2 is placed within the ends of the tube |01and without the tube |05; the concentric spacing rings ||3 are similarlypositioned between the ends of the tubes |00 and I 01; still largerconcentric spacing rings of cardboard H0 are placed between the ends ofthe tubes |09 and |08; a pair of larger concentric rings H5 are placedbetween the ends of the tubes I0 and |09 and the squared rings 6 areplaced on the outside of tube H0 at suitable points. All of these partsare suitably glued or cemented together. The cylinders or tubes may bemade entirely of a suitable type of bright metallic foil, if desired.

After these cylinders are so assembled, they are cut into four partsalong the lines I I1 and the line |1-I1. These assembled quartercylinders are then used as inserts and placed in the spaces adjacent thelperimeter of the rear wall of the cabinet.

In Fig. 18 another type of foil insulation is shown In this type,containers |20, |2| and |22 made of cardboard of a suitable type areshaped so as to t within the walls of a refrigerator cabinet and havemitered joints such as are shown at |23` and |20 so that the 'containersare :dt together at the corners of the cabinet. These containers arepreferably lled with a crnkled or corrugated foil insulation |25 so asto provide air spaces therein bounded by bright metallic foil. Ifdesired, the 'containers may be vfilled with foil of the type shown inFig. 6. s These containers are placed about the inner liner !26 between.the inner 4and outervwalls of the refrigerator cabinet. In this mannerthe insulation is provided in a form of foil insulation which may beeasily handled in the form of slabs.

While the form of embodiment of the invention as herein disclosedconstitutes aV preferred form, it is to be understood that other formsmight be adopted, all coming within the scope of the claims whichfollow.

What is claimed is as follows:

1. An insulated storage cabinet having inner and outer walls, andinsulation between said inner and outer walls including a plurality ofair spaces bounded by sheets `of bright metallic f oil, said foil beingembossed in a hammered form to prevent metal cry.

2. 'An insulated cabinet comprisinginner and outer Walls, insulationbetween said walls including a plurality of sets of sheets insuperimposed relation, each set of sheets comprising a corrugated sheetand a non-corrugated sheet, one of 35' relation, each set of sheetscomprising a corru-- said sheets being of' bright metallic foil and theother of said sheets being of a non-metallic matev rial.

3. An insulated cabinet comprising inner and outer walls, insulationbetween said walls including a. plurality of sets of sheetsinsuperimposed gated sheet and a non-corrugated sheet, one of said sheetsbeing of bright metallic foil and the other of said sheets beingof afibrous material, the corrugated sheet being attachedto thenoncorrugated sheet at the/tips of the corrugations. 4. An' insulatedcabinet comprising inner and outer walls, insulation between said wallsincluding a plurality of sets of sheets in superimposed relation, eachset of sheets comprising a sheet corrugated at spaced intervals-and anon-corru gated'sheet, one of said sheets being of bright metallic foil,and the other of said sheets being of said inner and outer wallsincluding a plurality of sheets of material wound-about said inner wallsa plurality of times providing a plurality oi superimposed layers, oneof said sheets of material being corrugated, one of said sheets ofmaterial being composed of bright metallic foil, and another of saidsheets being composed of fibrous material.

6. Aninsulated storage cabinet including inner and outer walls, andinsulating material between said inner and outer walls, including aplurality of sheets of material wound about. said inner walls aplurality of times providing a-plurality' of superimposed layers, one ofsaid sheets of material being corrugated, one of said sheets of materialbe-y ing composed of bright metallic foil, and another of said sheetsbeing composed of fibrous material, said corrugated sheets beingattached to other sheets at the tips of the corrugations.

7. An insulated storage cabinet including inner l and outer walls, andinsulating material between said inner and outer walls including aplurality of sheets of material wound about said inner walls a pluralityof times providing a plurality of superimposed layers, one of saidsheets of material being corrugated at widely .spaced intervals, one ofv said sheets of material being composed of bright metallic foil, andanother of said sheets being composed of fibrous material. l

8. An insulated panel-including a core slab, av sheet of bright metallicfoil wound about the core slab, a set of spacers fastened to oppositeedges of the core slab on top of the winding, and a sheet of brightmetal foil wound about said spacers to provide a plurality of spacedsheets of metal foil.

9. An insulated panel including a core slab, a sheet of bright metallicfoil wound about the core slab, a set of spacers fastened to oppositeedges -of the core slab on top of the winding, said sheet ing inner andouter walls, a separate insulation panel of generally rectangular shapebetween the inner and outer walls upon one side of the cabinet, saidinsulation panel including a framework of a low conducting material, a'plurality of embossed sheets of bright metallic foil mounted inspacedvrelation upon the frameworkforming a -plurality of gas spacesbetween the sheets, said foil being embossed for preventing metalliccry. i l

12. An insulatingV structure including a plurality of sheet portions,means for supporting the sheet portions in spaced relation with gasspaces in between, one of said sheet portions having air spaces on eachside and having metallic heat reilecting surfaces embossed forpreventingmetal cry. f v

13. An insulating structure'including a plurality of substantially planesheet portions, means for supporting the sheet portions in spacedrelationlwith gas spaces in between, one of the sheet ing of metal heatreflecting foil embossed for preventing metal cry. Y *14. An insulatingstructure having a wall portion. provided with a hollow enclosure, asheet of metallic heat reflecting foil within said enclosure ldividingsaid enclosure into a plurality of air spaces, saidy sheet beingembossed for pre venting metalcry. 15. An insulating` structurehaving awall portion provided with a hollow enclosure, a sheet -tion providedwith a'hollow enclosure. said enclosure being provided with a framework,'a sheet of metallicheat reiiecting foil supported by said frameworkvvin a stretched condition and extending across said enclosure dividingsaid enclosure into a. plurality of spaces, said- L EDMUNDF. SCHWELLER.,

4portions having air spaces on either side and besheet being em bossedfor preventing metalcry. '7G

